We have an app that dynamically generates PDF using FOP deployed on JBoss server running on AIX. My machine has IE 6 and Adobe Reader 8.1.2 with browser plug-in installed on Windows XP SP2.
PDF the app generates, doesn't open up within IE using the plug-in. But as I could save the PDF file and then open it using Adobe Reader, I went ahead and unchecked the option "Display PDF in Browser" (under Adobe Reader's Edit->Preferences->Internet). Doing so, opens up the PDF automatically using Adobe Reader instance outside of the browser. Though it works, I would like to avoid having all our users change their settings.
Another strange thing that I noticed is that when I run the app on my local machine with a windows version of JBoss, PDF opens up automatically w/o any issues in IE with Adobe plugin. But if the same code is deployed to the JBoss server on AIX it won't open in IE.
For testing purpose, I tried installing Foxit PDF reader, making it the default and PDF opens up fine under both Windows and AIX instances of JBoss.